How do I install this on a CPanel?

If you have licensed IPB forum you just install it from invisionpoweboard.com.
If you have a Nulled one, you need to upload to ftp server the forum files, and then you need to create a database name and user to conect forum files with database system.
There is a video: https://www.youtube.com/watch?v=Dv8ry4zVH_w